瑜伽論記 15.76

15.76

三品中，安足處煩惱，謂根熟者，性多上品者，景云：二十已上者力安是諸根成熟，爾時多起上品煩惱。

Regarding the three grades, the afflictions of a firm footing, meaning those whose faculties have matured, being mostly of the upper grade by nature: Jing says: For those aged twenty and above, whose strength is established, their various faculties have matured; at that time, they mostly arouse upper-grade afflictions.